Chapter 9 Flashcards
Genome
sum total of genetic material (DNA) in a cell
Chromosome
discrete cellular structure composed of a neatly packaged DNA molecule
Bacterial chromosome
Is single large circular dna containing most of the organism genetic material
Chromosome in eukaryotic cell
Chromosomes linear multiple set of dna
23 pairs in human eukaryotic cells
Alleles
Alternative members of a gene pair which may be homogenous or heterozygous
Purine
Adenine and guanine
Pyrmides
Cytosine and thymine
Present in bacteria and yeast small circular extra chromosomal dna capable of independent replication and contains genes for resistance and or fertility in some bacteria
Plasmid
Resistance plasmids which code for genes that Produce enzymes which act against antibiotics and drugs and other chemicals
R plasmids
F plasmids
Contains genes that code for f pili which serve as conjugation bridge for gene transfer during conjugation or sexduction
Replication
Process that uses existing dna to make new dna copies
Transcription
Uses dna to make rna copies
Translation
Uses rna to make protein products
mRNA
Messenger rna carries dna code to be translated into proteins
tRNA
Transfers rna carries amino acids to the ribosome during translation
Rrna
Ribosomal rna makes up the major part of the ribosome and participated in protein synthesis
Where does translation occur
Occurs in the ribsome if all cells
Proteins determine what
They determine phenotype
The eukaryotic gene is modified before it’s replicated or transcribed processing
Gene processing
Non coding dna segments or intervening sequence
Introns
Coding/functional dna segment
Exons
Gene expression begins with what
Replication
Are splicing enzymes which cuts off introns to join exons during gene processing
Splicesomes
An enzymes that joins the free dna ends forming a continuous piece binds or lighter dna fragments together
Dna ligase
unwinds and unzips the DNA double helix
•An RNA primer is synthesized at the origin of replication by a primase
Helicase
DNA polymerase III
then adds nucleotides in a 5′ to 3′ direction
removes the RNA primers and replaces them with DNA
DNA polymerase I
Minimizes formation of supoercoil
Dna gyrose
Transcription occurs where in eukaryotic cells and prokaryotic cells
Nucleus cytoplasm
Transcription uses how many strands
Single strand
Stop codons
UGA UAA UAG
Start codon
AUG
Binding of rna polymerase to the promoter Region that determines the specificity
Initiation
RNA polymerase adds nucleotides complementary to the DNA template strand in the 5′ to 3′ direction (Uracil (U) is placed complementary to adenine (A)
Elongation
RNA polymerase recognizes a “STOP” sign in the DNA and releases the transcript (100-1,200 bases long)
Termination
Removal of interims to join or reconnect exons
Genetic processing
Excessive amount of genetic product inhibit the genetic expression
End product inhibition
In prokaryotic cells set of genes sequestered and regulated or controlled by adjoining gene
Operons
Set of genes that regulate or is responsible for lactose metabolism in bacteria
Lac operant gene
What is lactose used for
Lactose is a disaccharide made of a glucose and galactose bacteria uses a glucose to make ATP and respiration
What components make up the LAC apron Gene
Regulatory or inducer gene
Proctor gene
Operator gene
Hydrolizes the lactose into it’s monosaccharide components
Betagalactoidase
Transports lactose across cell wall
Beta permease
This transports lactose across cell membrane
Transacetylase
When the inducible gene is continually on
Contituve induction
The indictable gene is permanent turned off due to mutation
Constitute repression
Permanent inheritable change in gene
Mutation
Mutant strains not able to grow on basic or minimum culture medium
Auxotroph
Normal or wild type organism that can grow on basic or minimal culture medium
Prototroph
